Effect of early rescue ICSI and split IVF-ICSI in preventing low fertilization rate during the first ART cycle: A real-world retrospective cohort study

Purpose To determine the utility of short gamete coincubation in in vitro fertilization (IVF-S) combined with early rescue intracytoplasmic sperm injection (R-ICSI) and split IVF-ICSI in preventing low fertilization based on a retrospective cohort study. Methods Couples with a high risk of low IVF fertilization during the first ART cycle underwent IVF-S with R-ICSI or split IVF-ICSI. Fertilization rate, embryo quality, and clinical outcomes were measured. Results After propensity score matching, we included 188 couples in the IVF-S with R-ICSI group as Group 1 and 720 in the split IVF-ICSI group as Group 2. Normal fertilization rates were similar; however, Group 1 had a higher multiple pronuclei rate (10.42% vs. 4.50%, p < 0.001) but a higher embryo utilization rate (59.84% vs. 53.60%, p < 0.001). The groups were similar in the rates of high-quality embryos, embryo implantation, clinical pregnancy, and live birth. Low IVF fertilization rate was 4.79% and 9.03% in Group 1 and Group 2, respectively, with similar fertilization rate and embryo development. Conclusion IVF-S with early R-ICSI and split IVF-ICSI were effective strategies in preventing low fertilization rate. IVF-S with early R-ICSI could become the preferred approach because of its advantages-higher embryo utilization rate, fewer ICSI procedures, similar clinical pregnancy rate, and live birth rate.